Nancy #🟦

Science, math, programming, tabletop games, @wsl. Following me is a privilege, not a right. Almost always block followers. Opinions are correct

[Nancy #🟦 @NancyPDoyle]

@greggnunziata Well said. These are character-defining moments.

[Sam שמואל @Tzioni2]

As Yom Kippur approaches, to everyone I’ve wronged, been mean to or been rude to this year, please take some time to reflect on what you did to make me act that way.

[Nancy #🟦 @NancyPDoyle]

@QuietLion @mcuban @grok Good question, Rich

[Nancy #🟦 @NancyPDoyle]

@legallurker528 @fedjudges agree, although they can’t be taking contrary positions.

[Nancy #🟦 @NancyPDoyle]

@BillAckman It is wonderful that you are funding this initiative. I am so sorry that Lucy underwent this. I pray for her continued recovery.

[Jesús Fernández-Villaverde @JesusFerna7026]

Last week I posted a new paper with Patrick Norrick: “Terra Incognita: The Economics of a Shrinking World.”

We chose the title deliberately. No society in history has experienced the fertility levels now seen in South Korea, China, Thailand, Colombia, Chile, and many other countries. Our knowledge of the causes (and of the economic consequences) remains far more limited than most public discussion acknowledges. Much of what we write is, at best, educated conjecture.

The paper also struggles against a space limit. We wrote 20,000 words, far from the 250,000 or so we would need to address some issues in more detail (if I had the time and resources to hide away for a year, I could do that, but not now). That means some ideas are only sketched.

Nonetheless, we emphasize several important points.

First, fertility has fallen very fast everywhere: rich and poor countries, east and west, north and south, conservative and liberal societies, religious and non-religious societies (with the exception of the Jewish population of Israel; fertility has also collapsed among the Muslim population within the pre-1967 borders), you name it. Even in sub-Saharan Africa we see fast and unprecedented drops in fertility (alas, from a high initial level).

Second, and this is really interesting, the fertility collapse has been concentrated in poor and lower-middle-income countries much more than in rich countries. By now, income per capita and fertility are positively correlated within OECD countries. We conjecture this will hold globally in a few decades.

Third, and related to the second point, the fertility collapse has been concentrated among poor and lower-middle-income women within countries. In countries such as the U.S., the rich and highly educated now have more children than the poor and less educated.

Fourth, we document why we do not understand the data from the U.N. World Population Prospects. See, for example, Tables A.1 and A.2.

Fifth, we explain why some proposed mechanisms struggle when confronted with the data.

A more subtle point is at work here. Many commentators do not seem to understand the difference between proximate causes and ultimate causes. Yes, births might have gone down because fewer women are in long-run relationships. That is the proximate cause. But you need to explain why fewer women are in long-run relationships (the ultimate cause), and saying that they spend more years in school, to take one example, does not get us very far. Why do they spend more years in school? Once you start down the whole chain of reasoning, things become much harder than they seem.

The paper can be found here:

https://t.co/VrCHr0lBPa

Comments always welcome!

[Grady Booch @Grady_Booch]

Water will find its way through cracks in walls and foundations in such a manner that even the most wondrously designed structure may collapse into pile of rubble.

Do not attribute agency to the water; rather, denounce the engineers and the builders and the maintainers who failed in their work.

[Stephen Wolfram @stephen_wolfram]

Sharing a great personal tragedy
https://t.co/TAZOM5MGLj

[Nancy #🟦 @NancyPDoyle]

@stephen_wolfram Wow. What a beautiful, human life.

[Nancy #🟦 @NancyPDoyle]

@QuietLion Dangerous but necessary, go slow

[Nancy #🟦 @NancyPDoyle]

@domainechambord @franceintheus @USAmbFrance @francediplo_EN @USEmbassyFrance @FranceinLA @FranceinChicago @HISTORY thank you. We remember your help during the American Revolution. France was a true ally! Great that you participated in the military flyover also.

[Nancy #🟦 @NancyPDoyle]

@Godstimelvis @netflix you are not alone!

[Nancy #🟦 @NancyPDoyle]

@QuietLion omg Zork!

[Massimo @Rainmaker1973]

How to fold and cut a stylish paper airplane

[Nancy #🟦 @NancyPDoyle]

@MatthewCappucci hi Matthew. This last week in Rehoboth Beach it’s been very hot. So local weather report has gotten an accurate but @MyRadarWX has consistently underestimated temp by about 10° the whole week. coastal areas are harder to forecast, but forecast for Delmarva Peninsula quite off.

[Andrew McCarthy @AJamesMcCarthy]

Pleased to share my favorite high-resolution capture of the Artemis II launch- the moment the SLS is clearing the tower, captured by a sound-triggered camera placed near the pad.

I'll have prints linked in my bio for this one, and here's a short thread about how it was captured

[Nancy #🟦 @NancyPDoyle]

@ayceman @Hamzythacreator This is my favorite

[Nancy #🟦 @NancyPDoyle]

@Yoda4ever @leonardkl I am not surprised that the corgi led the way.

[Remco de Boer @remcodb]

In ongekend felle bewoordingen heeft Zweden een streep in het zand gezet. Het conflict gaat over de integratie van het Europese elektriciteitsnet. Over geld, maar vooral over autonomie. Over meer of minder EU. Zie m'n LinkedIn-post voor achtergrond: https://t.co/H08dO28w91

[Nancy #🟦 @NancyPDoyle]

@kelly1952 @Britains___Pubs @VinnieSull1van @ChelseaDan5 Aw pubs make people feel welcome. Go! I actually believe it is almost impossible to be alone at, say, a Scottish pub if you are an American.